Re: [sig-policy] draft-submission - draft-wilson-class-e-00.txt
> As far as I'm aware, pretty much every version of every operating
> system out there (including Windows, MacOSX, Linux, etc) doesn't
> allow configuring 240/4.
That being the case it's certainly thornier than I anticipated. I believe
some of those fare better than others, but if you can't even route to a
prefix for backwards compatibility from a system I tend to agree it's likely
more of an uphill battle. I would have expected reachability to differ from
configurability (inet, routing) on the Windows platform, but they appear to
go hand-in-hand.
> The point is, this is a change of rules way late in the game in terms
> of software deployment and backwards compatibility is of high
> importance to folks trying to sell services on the address space
> allocated.
Fair point. Although one could argue that v6 is another reachability step
removed from that with regards to v4 hosts, and the systems that can't be
patched/upgraded would need a dual stack anyways.
[ ... ]
>From Paul Wilson's note:
> The benefit of private space is that each address can be used many times.
> Therefore the additional 16 blocks of private space proposed here could
> satisfy the need of a very large number of very large private networks,
> without consuming a single public address.
Understood. My impression was that public allocation requests were largely
because public addresses are needed, not because RFC 1918 private addressing
wasn't sufficient. In virtually all cases I've seen where RFC 1918 wasn't
sufficient, it was due to poor planning or implementation. Read: allocating
much more internal space than necessary despite possible future needs for
growth. This was usually a simple fix w/o the added need for public
addresses.
I've not witnessed the lack of private use addresses to be much of problem,
but perhaps a portion of public allocations are requested because of poor
internal private address planning. I suppose adding 240/4 to the available
private pool could alleviate some of this assuming they are willing to go
through the "pain" of being systems ready. It would be useful to have some
idea as to how much this will really help long term.
> On the other hand, if the space is redesignated as standard public unicast,
> then it can be used once only. At today's rate of consumption, this would
> add a year or so to the lifetime of IPv4. Add to this the greater
> difficulty of transitioning the entire Internet to deal correctly with
> 240/4 addresses (which is likened to the challenge of IPv6 transition), and
> I suggest the only viable alternative is private.
I think the added lifetime may be underestimated a bit as resources continue
to become more scarce and the value of IPv4 commodities rise, but those are
all certainly very valid points.
-- steve